Linux查找二进制文件

Question

I am attempting to find a binary file in a Linux system using something like this:

if [ -f `which $1` ] then
    echo "File Found"
else
    echo "File not Found"
fi

while the code works fine the problem is "which" will return a null operator which BASH interprets as something existing so a file always comes back found. Any suggestions would be great.

Thanks

Answer 1

Update

After a bit more thought, there is no reason to use [[ ]] (or [ ] for that matter). There is even no reason to use command substitution either $()

if which "$1" > /dev/null 2>&1; then
  echo "found"
else
  echo "not found"
fi

---

If you're using bash then please use the [[ ]] construct. One of the benefits (among many) is that it doesn't have this problem

[[ -f $(which $1) ]] && echo found

Also, `` is deprecated, use $() instead

Answer 2

if [ `which "$1"` != "" ]; then

which将不会返回""当它找到二进制。

Answer 3

I like 'hash' for this (if you're a bash user..) (and it's actually more portable behavior than which)

hash blahblah

bash: hash: lklkj: not found

hash /bin/ls <-- silently successful

This method works on Linux and OSX similarly, where-as 'which' has different behavior.